What are the adverse effects and management of iron sucrose (intravenous iron) overdose?

Iron Sucrose Overdose: Adverse Effects and Management

Iron sucrose overdoses typically present with milder toxicity than oral iron overdoses and can be managed with supportive care in most cases, without requiring deferoxamine therapy even with high serum iron levels. 1

Clinical Presentation of Iron Sucrose Overdose

Common Adverse Effects

• Standard therapeutic doses of iron sucrose commonly cause:
  • Dizziness
  • Headache
  • Hypertension
  • Injection-site reactions
  • Nausea (occurring in 1-10% of patients) 2

Overdose Manifestations

• Iron sucrose overdose typically presents with:
  • Elevated serum iron levels (can be significantly higher than oral iron overdose)
  • Minimal clinical toxicity compared to oral iron overdoses
  • Two-phase elimination kinetics (redistribution and elimination phases) 1
  • Possible abdominal pain (rare) 3

Key Differences from Oral Iron Overdose

Iron sucrose overdose differs significantly from oral iron salt overdose:

1. Lower clinical toxicity despite high serum iron levels
2. Absence of severe metabolic acidosis typically seen in oral iron poisoning
3. Lack of correlation between serum iron levels and clinical symptoms 1

Management Approach

Initial Assessment

• Evaluate vital signs with particular attention to blood pressure
• Assess for signs of toxicity:
  • Gastrointestinal symptoms (nausea, vomiting, abdominal pain)
  • Neurological status
  • Metabolic acidosis (check bicarbonate levels and anion gap) 1

Laboratory Monitoring

• Obtain serum iron levels
• Check complete blood count
• Monitor electrolytes, particularly bicarbonate
• Calculate anion gap
• Monitor serum phosphate levels (particularly with ferric carboxymaltose) 2

Treatment Protocol

1. Supportive Care:

   • IV hydration for mild hypotension 4
   • Symptomatic treatment
   • Close monitoring of vital signs

2. Observation:

   • Monitor serum iron levels every 4-6 hours until decreasing
   • Observe for at least 24 hours in significant overdoses 1

3. Deferoxamine Consideration:

   • Unlike oral iron overdose, deferoxamine may not be necessary even with very high serum iron levels (>1500 μg/dL) if the patient is clinically stable without metabolic acidosis 1
   • Reserve for cases with clinical deterioration or severe metabolic acidosis

4. Hemodialysis:

   • Consider in massive overdoses with life-threatening toxicity
   • Can significantly reduce serum iron concentration and improve clinical status in severe cases 5

Special Considerations

Rechallenge After Previous Reactions

• For patients who had previous reactions to iron sucrose:
  • Consider slower infusion rate (50% of initial rate)
  • Increase rate gradually if well tolerated
  • Consider alternative IV iron formulation if symptoms recur 4

Monitoring Duration

• Observe patients for at least 30 minutes following administration of IV iron 2
• For overdose cases, extended monitoring (24 hours) is recommended 1

Prevention Strategies

• Adhere to recommended dosing:
  • Standard dose: 200 mg IV over 30-60 minutes
  • Maximum single dose: 300 mg (doses of 400-500 mg associated with higher adverse event rates) 6
  • Total dose should not exceed 1000 mg 4, 2
• Ensure proper administration protocols:
  • Appropriate dilution
  • Correct infusion rates
  • Proper patient identification

Conclusion

Iron sucrose overdose presents with a distinct clinical profile compared to oral iron overdose, with generally milder toxicity despite high serum iron levels. Management should focus on supportive care and monitoring, with consideration of hemodialysis only in severe cases with clinical deterioration.